Vehicles, such as aircrafts, and other machinery employ seals to connect static and moving parts within the machinery and to control a fluid flow between the parts. In a gas turbine engine, seals are located in numerous locations such as on rotors, input shafts, output shafts, etc., and can be used in numerous systems such as motors, generators, transmissions and gearbox assemblies to name a few.
According to one implementation, seals may be employed in a spline joint connecting two rotatable members. The seal may be arranged at an interface between a spline shaft and a sleeve shaft, such as on a driveshaft or a propshaft. The spline area is provided with a lubricating fluid, such as oil, in an attempt to reduce wear on the spline joint teeth. However, merely allowing a lubricating fluid to pass over the splines may be inadequate because the lubricating fluid is thrust outwardly or radially from the rotating members due to high rotational speeds and loads such that the contact area of the spline teeth experience insufficient lubrication.
In order to improve the service life of the spline joint, a seal, such as an o-ring seal, has been employed to form a barrier on one side of the spline joint thereby halting the fluid flow in an effort keep the spline area submerged in the lubricating fluid. However, these seals provide a fluid-tight connection with no ability to permit the lubricating fluid to flow-through and exit the spline joint. As such, heat generated due to misalignment or operating conditions cannot be removed and debris generated by spline wear is trapped thereby reducing component part life and accelerating wear. Moreover, dirt or other debris may be trapped at the interface which may potentially reduce the service life of the spline joint.
Accordingly, there is an established need for a seal that lubricates a spline joint effectively and permits the lubricating fluid to flow-through the spline joint providing cooling and debris removal, while providing a relatively simple and economical construction.